mumbai, May 21 -- Starting 29 May, India's first exchange-traded rainfall derivatives contracts will be open for trading to retail and high-net-worth investors, power utilities, logistics firms and agri-processing businesses, among others. On Wednesday, NCDEX unveiled its rainfall index, RainMumbai. The futures index contracts will be available for trading from 29 May to 30 September, the period of the south-west monsoon. Futures contracts represent the expected spot price on a future date. "This is the first-of-its-kind index globally and we expect it to cater to a whole host of sectors that are exposed to rainfall risks," said Arun Raste, managing director & CEO of NCDEX. "CME is the other exchange-traded weather derivative contract avail...